甜菜碱对肉鸡脂肪代谢、肌肉品质及抗氧化功能的影响

发布时间：2018-01-26 05:11

本文关键词： 甜菜碱肉鸡脂肪代谢肉品质热应激氧化还原状态　出处：《南京农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：甜菜碱可降低肉鸡的脂肪沉积,改善胴体组成及肉品质,提高抗氧化功能,但关于其对肉鸡脂肪代谢及肉品质的影响研究尚不够深入系统,对热应激肉鸡抗氧化状态的影响亦尚未见报道。为此,本文以AA肉鸡为试验对象,研究甜菜碱对肉鸡脂肪代谢、肉品质及抗氧化功能的影响,以期为甜菜碱在肉鸡饲料中的合理应用提供理论依据。本文分为以下三个部分:试验一旨在研究不同添加量甜菜碱对肉鸡脂肪代谢的影响。选用240只1日龄健康AA肉鸡随机分为5组,每组6重复,每重复8只。对照组饲喂基础日粮,试验组分别在基础日粮中添加250、500、750、1000 mg/kg甜菜碱。结果表明,日粮中添加甜菜碱对肉鸡的生产性能及血清生化指标均无显著影响(P0.05)。随着甜菜碱添加量增加降低了肉鸡绝对和相对腹脂重(linear P0.05,quadratic P0.01)和肉鸡血清中低密度脂蛋白胆固醇(LDL-C)、甘油三脂(TG)、总胆固醇(TC)含量(linear P0.05),但提高了游离脂肪酸(NEFA)含量(linear P=0.038,quadratic P=0.003)。随着甜菜碱添加量增加肉鸡肝脏中PPARα、CPT-I、HADH基因mRNA表达量呈线性提高,但肝脏中FAS、HMGR基因mRNA表达量呈线性降低(P0.05)。试验二旨在研究不同添加量甜菜碱对肉鸡屠宰性能、胸肌肉品质及其抗氧化功能的影响。试验设计同试验一。结果表明,与对照组相比,日粮中添加750 mg/kg甜菜碱显著提高了肉鸡胸肌率(P0.05);随着甜菜碱添加量增加提高胸肌粗蛋白含量(linear =0.001,quadratic P=0.044),但对胸肌粗脂肪及水分含量均无显著影响(P0.05)。随着甜菜碱添加量增加胸肌48 h滴水损失呈线性降低(P0.05);与对照组相比,日粮中添加甜菜碱有降低胸肌压力损失的趋势(P0.1),但对肉鸡胸肌肉色(亮度、红度和黄度)、pH值、24 h滴水损失和蒸煮损失均无显著影响(P0.05)。随着甜菜碱添加量增加胸肌中T-SOD活力呈线性提高(P0.05);与对照组相比,甜菜碱添加显著降低了胸肌中MDA含量(P0.05);添加750 mg/kg甜菜碱显著提高了胸肌中GSH含量(P0.05),添加250、500 mg/kg甜菜碱有提高肉鸡胸肌GSH含量的趋势(P0.1);甜菜碱添加对GPX活力无显著影响(P0.05)。试验三旨在研究甜菜碱对热应激肉鸡生产性能和氧化还原状态的影响。选用144只体重相近的21日龄肉鸡随机分为3组,每组6重复,每重复8只,试验期为21-42 d。对照组肉鸡在常温条件下饲喂基础日粮;其余两处理组肉鸡从9:00到17:00(8 h)维持温度在34 ± 1 ℃,其他时间维持常温,分别饲喂基础日粮和添加1000 mg/kg甜菜碱的基础日粮。结果表明,与对照组相比,热应激组肉鸡平均日增重(ADG)和平均日采食量(ADFI)显著降低(P0.05),肉鸡直肠温度及鸡冠温度和血清中天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性及肝脏丙二醛(MDA)的含量显著提高(P0.05),肝脏及肝脏线粒体中超过氧化物歧化酶(SOD)、谷胱甘肽氧化物酶(GPX)活性和肝脏中过氧化氢酶(CAT)活性、谷胱甘肽(GSH)含量及谷胱甘肽(GSH)/氧化型谷胱甘肽(GSSG)比值显著降低(P0.05)。与热应激组相比,日粮中添加甜菜碱对肉鸡ADG和ADFI有提高趋势(P0.1),显著降低了血清中ALT活性和肝脏中MDA含量(P0.05),且增加了 CAT活性、GSH含量、GSH/GSSG比值和肝脏及肝脏线粒体SOD和GPX活性(P0.05)。与对照组相比,热应激组肉鸡肝脏GPX及禽解偶联蛋白(avUCP)基因mRNA表达量下降;而甜菜碱提高了热应激肉鸡肝脏GPX及avUCP基因mRNA表达量(P0.05);各处理组肝脏SOD和CAT基因mRNA表达量无显著差异。综上所述,得出以下结论:(1)日粮中添加甜菜碱对肉鸡生产性能无显著影响,但显著降低肉鸡腹脂沉积且呈现剂量效应;腹脂沉积降低可能与FAS基因mRNA表达量下调和PPARα、CPT-I及HADH基因mRNA表达量上调有关。(2)日粮中添加750mg/kg甜菜碱能有效提高胸肌率,且能提高胸肌肉中粗蛋白含量、增强胸肌系水力及胸肌的抗氧化功能,改善肌肉品质。(3)日粮中添加甜菜碱缓解了热应激对肉鸡生产性能和氧化还原状态的负面影响,表现为提高了 ADG、ADFI和肝脏及其线粒体的抗氧化功能。
[Abstract]:Betaine can reduce fat deposition in broilers, improve carcass composition and meat quality, improve the antioxidant function, but for the study of chicken fat metabolism and the effect of meat quality is not deep enough, influence on the antioxidant status of broilers also has not been reported. Therefore, this paper takes AA broilers as test object, the Research of betaine on Broilers fat metabolism, affecting meat quality and antioxidant function, so as to provide theoretical basis for reasonable application of betaine in broiler feed. This paper is divided into the following three parts: a test was conducted to study the effects of different amount of betaine on lipid metabolism of broilers. A total of 240 1 day old AA broilers were randomly divided into 5 group, consisting of 6 replicates of 8 birds per replicate. The control group was fed basal diet, the test group were added 2505007501000 mg/kg betaine in the basal diet. The results showed that the addition of beet alkali in diets on meat There were no significant effects of chicken production performance and serum biochemical indexes (P0.05). With the addition of betaine reduces the absolute and relative weight of abdominal fat in broilers (linear P0.05, quadratic P0.01) and serum low density lipoprotein cholesterol (LDL-C), glycerin three greases (TG), total cholesterol (TC) content (linear P0.05), but increased the free fatty acid (NEFA) content (linear P=0.038, quadratic P=0.003). With the addition of betaine PPAR alpha, broiler liver CPT-I, HADH gene expression of mRNA showed a linear increase, but the liver FAS, HMGR gene expression of mRNA decreased linearly (P0.05). Experiment two aims to study different amount of betaine on slaughter performance of broilers, affect the quality of chest muscle and its antioxidant function. With a pilot experimental design. The results showed that compared with the control group, adding 750 mg/kg betaine diets significantly improved broiler breast muscle ratio (P0.05) with; With the addition of betaine improve muscle crude protein content (linear =0.001, quadratic P=0.044), but the crude fat and muscle moisture content had no significant effect (P0.05). With the addition of 48 h betaine muscle drip loss decreased linearly (P0.05); compared with the control group, dietary supplementation with betaine muscle decreased the pressure loss of the trend (P0.1), but on the broiler breast muscle color (brightness, red and Huang Du), pH value, have no significant effect on 24 h drip loss and cooking loss (P0.05). With the addition of betaine increased linearly with increase in muscle activity of T-SOD (P0.05); compared with the control group, the addition of betaine the MDA content was significantly reduced in muscle (P0.05); add 750 mg/kg betaine significantly increased the content of GSH in muscle (P0.05), adding 250500 mg/kg betaine improve broiler breast muscle GSH content trend (P0.1); the addition of betaine had no significant effect on the activity of GPX Ring (P0.05). Experiment three aims to study the effect of betaine reduced heat stress in broiler production performance and oxidation. A total of 144 21 day old broilers were randomly divided into 3 groups of similar weight, consisting of 6 replicates of 8 birds per replicate test period for 21-42 D. control group of broilers under normal temperature conditions based on feeding grain; the remaining two broilers from 9:00 to 17:00 (8 h) to maintain the temperature at 34 - 1 DEG C, maintain normal temperature the rest of the time, and were fed basal diet supplemented with 1000 mg/kg betaine based diets. The results showed that compared with the control group, heat stress group broilers average daily gain (ADG) and average daily feed intake (ADFI) decreased significantly (P0.05), aspartic acid transaminase and temperature and rectal temperature of broiler comb in serum (AST) and alanine aminotransferase (ALT) activity and malondialdehyde (MDA) content increased significantly (P0.05), liver and liver mitochondria in superoxide dismutase (S OD), glutathione peroxidase (GPX) and catalase activity in the liver (CAT) activity, glutathione (GSH) content and glutathione (GSH) / oxidized glutathione (GSSG) decreased (P0.05). Compared with the heat stress group, adding betaine diets improving trend of Broilers and ADFI (ADG P0.1), decreased the content of MDA in liver and serum ALT activity (P0.05), and increased CAT activity, GSH content, GSH/GSSG ratio and hepatic mitochondrial SOD and GPX activity (P0.05). Compared with the control group, heat stress group of chicken liver GPX and avian uncoupling protein (avUCP) gene mRNA expression and improve the thermal stress; Betaine GPX and avUCP gene expression of mRNA in liver of broilers (P0.05); the treatment group liver SOD and CAT gene expression of mRNA had no significant difference. In summary, draw the following conclusions: (1) adding betaine diets significantly on production performance of Broilers The effect, but significantly reduced abdominal fat deposition in Broilers and showed a dose effect; reduce abdominal fat deposition may be decreased and PPAR alpha and FAS gene expression of mRNA, CPT-I and HADH gene expression of mRNA. (2) add 750mg/kg betaine diets can effectively improve the rate of breast muscle, and can improve the content of crude protein in high chest in the muscle, enhance the antioxidant function of pectoral muscle and breast muscles of hydraulic system, improve the quality of muscle. (3) add betaine diets alleviate heat stress reducing negative effect on production performance and oxidation state of broilers, showed increased ADG, ADFI and liver mitochondria and its antioxidant function.

【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S831.5

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